85 245 dl b230

I am chasing a hot start problem . There seems to be 3 temp sensors on this engine plus the oil sending unit. Two have a single wire and one with two wires. Which one is which??? One of these should feed the temp gage, one for the ECU And one for the I don't know.

Bob

The sensor near the rear of the engine and up under the intake manifold should have two wires to it. This is the temp sensor for the ECU. Forward of that one and up under the intake manifold is a sensor with a single wire connection (yellow, I recall). This is the sensor for the temp guage. Forward of that and lower is the spark knock sensor, not a temp sensor.

Thank You!!!

Any idea what resistance I should see across the two wire sensor????

Bob

The resistance will vary with temperature. The Bentley manual shows this on page 241-12. The resistance drops from about 7000 at 32 deg. F. to about 250 ohms at 190 deg. F. The procedure foe measuring this resistance is given in the Bentley manual. It involves measurements at the connector to the ECU taken with the connector disconnected from the ECU. There are warnings about NOT making electrical tests with the connector on the ECU. I suppose you could disconnect the temperature sensor at the block and measure its resistance directly but the area is very cramped. I haven't had to go in and make these tests at the ECU so I don't feel qualified to go further in advising you.
If you can get a copy of the Bentley, you won't regret it.